Magnetic drive



June 10, 1947. L. T. RADER 2,422,040

MAGNETIC DRIVE Filed Jan. 27, 1945 Flg- I. 30

46 Inventor I Louis T Fiadefi by )i ww 2 His Attorney.

Patented June 10, 1947 an... Schenectady, Nix. aalignor to eral ElectricCompaima corporation of Louis '1. Gen New York Application mm, 27, 1945,Serial No. 514,904 7 Claims. 112-484) My invention relates to magneticdrives, more particularly to a magnetic drive for a member in a sealedchamber, such as a' valve in a sealed pipe, and has for its objectsimple, reliable and efficient magnetic drive means utilizing permanentmagnets.

In carrying out my invention in one form, I utilize an annular statormember which is mounted for limited angular movement and which is madeup into a plurality of arcuate segments having their ends in spacedrelation. Across each pair of spaced ends of the arcuate members Iprovide permanent magnet means for producing a magnetic field wherebythe ends orpoles of the magnet are constituted by the two arcuatemembers. Inside of the so-called stator member, I provide a circularrotor member which is mounted for limited angular movement, and

which is separated from the surrounding stator member by a thin annularlayer or sheet of nonmagnetlc material. This layer of nonmagneticmaterial, furthermore. closes a sealed chamber in which is mounted therotor member. The adiacent spaced surfaces of the stator member andinner rotor member, separated by the nonmagnetic sheet, are providedwith teeth which form a plurality of poles, whereby the magnetic fieldset up by the permanent magnets apply a force to hold the teeth in apredetermined registering relation dependent on the torque exerted onthe inside rotor teeth by the mechanism to which the disc 8 is providedwith a central tubular member ill surrounding the shaft 4 and having itsthey are attached. Thus, when the stator memher is turned by suitablemeans, as by an electric motor, the inner rotor member is turned withthe stator member \by' reason of the magnetic attraction between theteeth, but with an angle of displacement between them.

For a more complete understanding of my invention, reference should behad to the accompanying drawing, Fig. 1 of which is a side elevationview partly in section of a magnetic drive embodying my invention; Fig.2 is a view in section taken along the line 2-2 of Fig. 1 looking in thedirection of the arrows; while Figs. 3 and 4 are fragmentary sectionalviews showing modified forms of my invention.

the magnetic members "-22 and the side clamp tion with the outer surfaceof the sheet I. The

the rotor or driving member 5 in a chamber desealed together at theirperipheries by a thin annular sheet-or diaphragm l made of nonmagneticmetal, such as Monel metal. At its center, the disc member I is providedwith a hub cap 9 which encloses and seals the end of the shaft I andalso provides a bearing for the shaft 4, while outer ,or left-hand endsecured and sealed to the pipe 2, Likewise, the tubular member I. isprovided with an internal bearing for the shaft 4. An enclosing cap H isprovided for the outer end of the pivot shaft 3. Thus, this constructionseals fined by the discs l and I and the peripheral sheet I, whichchamber communicates through the bearing in the member ll with thechamber constituted by the pipe 2.

For strengthening purposes, a plurality of metal studs II, II and I areprovided extending between the end plates 6 and I and having their endssecured to the plates. Preferably, as shown, the ends of the studs arereduced in size to provide shoulders for the plates 6 and I whereby theplates are especially strengthened against external or internalpressures such, for example, as would be applied by the air in the eventof a partial or complete vacuum or pressurized gas in the enclosedchamber.

The rotor member I comprises a hub i5 secured to the shaft I and athree-legged spider support It connecting the hub II with an outerannular rim member l'l made of magnetic material. On

its outer periphery, this rim is provided with a plurality of equallyspaced teeth ll extendin parallel with the shaft 4. The outer ends ofthese teeth I! are in closely spaced relation with the inner surface ofthe sheet I.

Surrounding the rotor member is a stator or driving member consisting offour arcuate shaped pole piece members it, 20, 2i and 22 made ofmagnetic material which are clamped between two annular members 23 and24, the inner edges of which are mounted at 26 and "a 0n the peripheriesof the two disc members 8 and l so that the stator driving memberassembly, including ing members 23 and 24, can be turned on the end discmembers 6 and I thereby to turn with them the rotor l. The annularmembers 23 and 24 are made of a nonmagnetic material, such as brass. Onthe inner walls of the members "-22 inclusive are spaced teeth 25b,theends of which form pole faces and are in closely spaced rela- 3angular spacing between the teeth 25b is the same as the angular spacingbetween the teeth II on the rotor member, and the actual circumferentialspacing and width of the teeth in the two sets is the same except forthe slight dii'ference caused by the fact that the teeth 12 have asmaller radius.

For thepurpose of creating a magnetic flux thereby to hold the rotormember in a predetermined angular relation with the stator member,permanent magnets 26, 21, 28 and 29 are provided. These magnets arehorseshoe-shaped and extend across the gaps or spaces between theadjacent ends of each pair of the magnetic members l9-22. Thus theadJacent ends of the members I9 and 22 are separated by an air gap 30,and the magnet 28 extends across this air gap with its ends secured tothe outer peripheral surfaces of the members I! and 22 at points nearthe ends of the members. The magnets 21, 22 and 29 are similarlyarranged with respect to the other magnetic members. The magnets aremounted on the stator member with poles of like polarity adjacent eachother. Thus, for example, the south poles of the magnets 22 and 22 aresecured to the magnetic member 22, while the north poles of the magnets28 and 21 are secured to the member l9, etc.

Thus the magnets produce each a magnetic field which passes from one endof the magnet through the adjacent teeth 25b in the stator, through thenonmagnetic sheet 2 and air gaps to the teeth l8, and through the rim 11across the air gaps and sheet 2 back to the other pole of the magnet.Thus, magnetic attractive forces are produced between the teeth oi thestator and rotor members, which forces tend to hold the rotor member inan angular relation with the stator member which is dependent on torqueexerted on the rotor so that when the stator member is turned in eitherdirection, the rotor member is turned with it, whereby the valve I isturned. It will be observed that the rotor has sufllcient freedom withrespect to the racing studs or pins i 2, l2 and I 4 to provide forsubstantially ninety degrees rotation to provide for movement of thevalve l between fully closed and fully opened positions.

For driving the rotor member, segment 3| which is secured to ring 23.Cooperating with this segment 2| is a driving gear 22 which is connectedthrough a speed reducing gear drive 22 to an electric driving motor 24so that the gear 22 is driven at only a fraction of the speed of themotor.

In a modified form of my invention shown in Fig. 3, I provide an annulargroove 22 in the periphery of the rim 21 whereby the projections orteeth 28 are divided each into two portions of equal length, the groove22 extending into the rim below the bases of the teeth, thereby to forman air gap between the two rowsoi' teeth. In this form, the permanentmagnets 22 (only one of which is shown) are arranged parallel with theaxis of rotation of the rim 21 and bridge the space between two annularmembers 42 and 41 made of magnetic material, these members being mountedon the annular supporting members 42 and 42 which are similar to themembers 22 and I provide a gear 24 of Figs. 1 and 2. On the innercircumferences of the members and 4| are teeth 44 and 42 having the samespacing as the teeth 22 and having their ends in closely spaced relationwith the outer face of the sheet 40, the teeth 3! being the end annularhigh coercive force in 4 in closely spaced relation with the innersurface of the diaphragm.

With this arrangement, it will be observed that each magnet produces amagnetic iield which passes from one pole face constituted by the endsof the teeth through the nonmagnetic sheet 48 to the teeth 22 on oneside of the rim, then across the rim to the teeth on the other sidethrough the nonmagnetic sheet back to the magnet. Thus the statorconstituted by the supports 42 and 42 and the members carried by it ismagnetically locked with the rim or rotor and rotation of the statorcarries the rotor with it.

Preferably, I make the permanent magnets for my device from a materialhaving a relatively relation to its sine. A suitable material for thispurpose is an alloy comprising by weight 6-15 per cent aluminum, 12-30per cent nickel, and about 5 per cent copper if desired, the remainderbeing iron, such as described and claimed in U. 8. Patents Nos.1,947,274 and 1,968,569, issued on February 13, 1934,. and July 31,1934, respectively, to William E. Ruder.

In the modified iorm of my invention shown in Fig. 4, I provide a solidring 41 made of magnetic material on the inside of which are mounted aplurality of bar magnets 42 extending radially with respect'to themember 41. As shown, eight of these bar magnets equally spaced aroundthe ring are provided. These magnets are magnetized with their oppositepoles on their radial extremities and further arranged with their polesalternating in engagement with the member 41.

Each magnet 42 is provided with a pole piece 42 made of magneticmaterial whose inner face adiacent the layer 0! nonmagnetic material 22is cylindrical and provided with equally spaced pro Jections 5! havingthe same'spacing as the proiections 22 on the rotor member 22 which hasthe same construction as the rotor member i1 of Fig. l. The crosssection of the pole pieces 42 may be the same as the cross section ofthe pole pieces ll-22 inclusive of Fig. 1. The pole pieces 42 areclamped between two annular rings 54 similar to the rings 22 and 24 ofFigs. 1 and 2, only one of the rings 54 being shown in Fig. 4. The rings24, carrying the annular member 41, the

, magnets and the pole pieces, are rotatably supported upon a pair ofstationary plates 62, similar to the plates 2 and 1 of Figs. 1 and 2.

If desired, for the purpose of reducing the cost of construction, thepole pieces 42 may be made from plates of magnetic material in whichparallel grooves forming the teeth 5| are out, after which the surfacesof the teeth are machined to give them an arcuate form on their innerends.

While I have shown a particular embodiment of my invention, it will beunderstood, of course, that I do not wish to be limited thereto sincemany modifications may be made, and I therefore contemplate by theappended claims to cover any such modifications as fall within the truespirit and scope of my invention. I

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. A magnetic drive comprising a rotor member provided with a rim ofmagnetic material and with equally spaced axially extending teeth on itsperiphery, an enclosure for said rotor member including a layer ofnonmagnetic material surrounding said rotor member having its innersurface adjacent th ends of said teeth, a stator member including aplurality of arcuate magmeans rotatably supporting saidmagnetic membersin spaced relation witheac other adjacent said layer of nonmagneticmaterial, a plurality of permanent magnet means secured to said magneticmembers so as to bridge same spaced relation as said teeth on said rotormember whereby magnetic driving forces are set up between said statorand rotor members, and means for turning said stator member thereby toturn said rotor member with said stator member.

2. A magnetic drive comprising a rotor member provided with a rimcfmagnetic material and with equally spaced axially extending teeth on itsperiphery, an enclosure for said rotor mem-' ber including a layer ofnonmagnetic material surrounding said rotor member having its innersurface adjacent the ends of said teeth, a stator member including aplurality of arcuate ma netic members, means rotatably supporting saidarcuate members in peripheral spaced relation with each other aroundsaid rotor member, a plurality of permanent magnets mounted to bridgesaid magnetic members, a plurality of teeth on the inner surfaces ofsaid arcuate members adjacent the outer, surface of said layer ofnonmagnetic material having substantially the same spaced relation assaid teeth on said rotor member whereby magnetic driving forces are setup between said stator and rotor members, and means for turning saidstator member thereby to turn said rotor member with said stator member.I

3. A magnetic drive comprising a rotor member provided with a rim ofmagnetic material and with equally spaced axially extending teeth on itsperiphery, a stationary end disc on each side of said rotor member, alayer of nonmagnetic material joining the peripheries of said discshaving its inner surface adjacent the ends of said teeth, a statormember including a pair of annular members rotatably mounted on said enddiscs, at least one of said annular members being made of non-metallicmaterial, a plurality of arcuate magnetic members secured between saidannular members in spaced relation with each other, a plurality ofpermanent magnets mounted to bridge said magnetic members and securesaid magnetic members together, a plurality of teeth on the innersurfaces of said arcuate members adjacent the outer surface of saidlayer of non magnetic material having substantially the same spacedrelation as said teeth on said rotor member whereby magnetic drivingforces are set up between said stator and rotor members, and means forturning said stator member thereby to turn said rotor member with saidstator member.

4. A magnetic drive comprising a rotor member provided with a rim ofmagnetic material and with equally spaced axially extending teeth on itsperiphery, a stationary end disc on each side of said rotor member, alayer of nonmagnetic material joining the peripheries of said discshaving its inner surface adjacent the ends of said teeth, a statormember including a pair of annular members rotatably mounted on said enddiscs, a plurality of arcuate magnetic members secured between saidannular members in peripheral spaced relation with each other, apermanent magnet mounted to bridge each'space between adjacent ends ofsaid arcuate members, like poles of adjacent magnets being associatedwith opposite ends of each of said arcuate members. a plurality of teethon the inner walls of said arcuate members havingsubstantially the samespaced relation as said teeth on said rotor member whereby magneticdriving forces are set up between said stator and rotor members, andmeans for turning said stator member thereby to tum said rotor memberwith said stator member. 7

5. A magnetic drive comprising a first driving rotormember provided witha rim of magnetic material and with equally spaced axially extendingteeth on its periphery, a support for said first driving memberincluding a layer of nonmagnetic material surrounding said first drivingmember having its inner surface adjacent the ends of said teeth, asecond driving member including a pair of annular magnetic memberssurrounding said first driving member, means rotatably supporting saidannular magnetic members in spaced relation with each other adjacent theouter surface of said layer of nonmagnetic material, a plurality ofpermanent magnets secured to said annular members with the ends of eachof said magnets connected respectively to said annular members and withlike poles of said magnets connected to each of said annular members, aplurality of teeth on the inner surfaces of said annular membersadjacent the outer surface of said layer of nonmagnetic material havingsubstantially the same spaced relation as said teeth on said rotormember whereby magnetic driving forces are set up between said drivingmembers, and means for turning one of said driving members thereby toturn the other of said driving members.

6. A magnetic drive comprising a rotor member provided with a rim ofmagnetic material and with equally spaced axially extending teeth on itsperiphery, an enclosure for said rotor member including a layer ofnonmagnetic material surrounding said rotor member having its innersurface adjacent the ends of said teeth, a stator member including apair of annular magnetic members surrounding said rotor member, meansrotatably supporting said magnetic members in spaced relation with eachother adjacent the outer surface of said layer of nonmagnetic material,a plurality of permanent magnets secured to said annular members withthe ends of each of said magnets connected respectively to said annularmembers and with like poles of said magnets connected to each of saidannular members, a plurality of teeth on the inner surfaces of saidannular members adjacent the outer surface of said layer of nonmagneticmaterial having substan tially the same spaced relation as said teeth onsaid rotor member whereby magnetic driving forces are set up betweensaid stator and rotor members, and means for turning said stator memberthereb to turn said rotor member with said stator mem er.

7. A magnetic'drlve comprising a rotor member provided with a rim ofmagnetic material and with equally spaced axially extending teeth on itsperiphery, a stationary disc member on each side of said rotor member, alayer of nonmagnetic material joining the peripheries of said discs withits inner surface adjacent the ends of said teeth, a pair of annularmembers made of nonmagnetic material rotatably mounted on said discs, apair 8 and rotor members, and means for turning said stator memberthereby to turn said rotor member with said stator member.

LOUIS T. RADER nnrnnnncns man The following references are of record inthe iile of this patent:

UNITED STATES PATENTS Number a Name Date 1,911,980 Lipman May 30, 19332,131,035 Beec yn Sept. 27, 1938

